The Clinical Core is the hub of the CRC's scientific enterprise. Its principle mission is to provide the clinical methodology and resources necessary to pursue the CRC's over-arching theme: identification of heterogeneous syndromes of geriatric mood disorders with distinct outcomes, mechanisms and treatment responses. The Clinical Core has fulfilled its subject recruitment target (N=235), maintained a low attrition rate (a total 9.75% over 4 years), obtained R01 funding for both proposed pilot projects, and trained numerous investigators, four of whom received Career Development Awards (K07). Its studies on the course and outcomes of geriatric mood disorders have provided the conceptual basis for the mechanistic hypotheses of the CRC. The Clinical Core will provide the Entry Assessment to all CRC subjects who agree to participate in CRC-related studies. In 400 of these subjects, the Core will provide Extensive Assessment and Follow-up, including clinical, neuropsychological and psychosocial ratings, and arrange for laboratory testing. Inclusion of both psychiatric and medical patients (N=150) in its sample will allow the CRC to study depressed elderly patients with a broad range in severity and type of medical co-morbidity. The Clinical Core proposes to test cross-core hypotheses that originated from the CRC's preliminary findings: 1): medical co-morbidity, vascular risk factors, cognitive impairment and pathophysiological disturbances predict chronicity of geriatric depression; 2) residual depression, cognitive impairment, emerging medical illness, life adversity, neuroticism, poor adaptation and pathophysiological abnormalities predict early relapse/recurrence; and 3) continuation and maintenance treatment of subjects assigned to controlled post-recovery pharmacotherapies will have greater efficacy than placebo or naturalistic uncontrolled treatment. In addition, the Clinical Core will continue to conduct methodological studies and provide training and quality control of diagnostic and clinical rating procedures. Finally, the Core will remain the primary research training resource on the methodology of longitudinal investigation geriatric research fellows (M.D. and Ph.D.), for the Medical College and the broader scientific community.